Mitsubishi Electric C70 Setup Manual page 607

MITSUBISHI CNC
Appendix 2 Explanation of Alarms
[6] The rotation does not stabilize.
Investigation item
Check the spindle parameter SP005 (SP008)
1
settings.
Manually shake the speed detector connectors
2 (spindle drive unit side and speed detector side)
to check if they are disconnected.
Turn the power OFF, and check the connection
3 of the speed detector cable with a tester.
(Especially check the shield wiring.)
Investigate the wiring and installation
environment.
4 1) Is the ground correctly connected?
2) Are there any noise-generating devices near
the drive unit?
[7] The speed does not rise above the command speed sometimes.
Investigation item
Check the speed command.
1 Check whether the override input is input from
the machine operation panel.
Check whether the load has suddenly become
2
heavier.
Manually rotate the motor bearings and check
3
the movement.
Manually shake the speed detector connectors
4 (spindle drive unit side and speed detector side)
to check if they are disconnected.
Turn the power OFF, and check the connection
5 of the speed detector cable with a tester.
(Especially check the shield wiring.)
590
Investigation results
The rotation stabilizes when the settings
values are both set to approx. double.
The symptoms do not change even when the
above value is set.
The connector is disconnected (or loose).
The connector is not disconnected (or loose). Check the investigation item No. 3.
The connection is faulty.
The connection is normal.
1) The grounding is incomplete.
2) The alarm occurs easily when a specific
device operates.
No particular problems found.
Investigation results
The speed command is not input correctly.
The speed command is input correctly.
The load has become heavier.
No particular problems found.
The bearings do not rotate smoothly.
The bearings rotate smoothly.
The connector is disconnected (or loose).
The connector is not disconnected (or loose). Check the investigation item No. 5.
The connection is faulty.
The waveform is normal.
Remedies
Change the setting value.
Note that the gear noise may increase.
Return the setting values to the original values.
Check the investigation item No. 2.
Correctly connect the connector.
Replace the detector cable.
Correct the connection.
Check the investigation item No. 4.
Correctly ground.
Use noise measures on the device described
on the left.
Replace the spindle drive unit.
Remedies
Input the correct speed command.
Check the investigation item No. 2.
Repair the machine side.
Check the investigation item No. 3.
Replace the spindle motor.
Check the investigation item No. 4.
Correctly connect the connector.
Replace the detector cable.
Correct the connection.
Replace the spindle drive unit.